Abstract

The project originates from the National Science and Technology Supporting Program, named“The Research on Cycloid Enveloping Planetary Precision Transmission”(No. 2006BAF01B08). Precision transmission is a kind of mechanical transmission mainly focuses on transmitting movement in high precision, it is widely used in many areas, such as aviation and spaceflight, weaponry and equipment, NC machine tools, robot, precision machinery, printing and packaging machinery, transportation machinery, medical apparatus and so on. Precision transmission is an important basic component in manufacturing and equipment industry, national defense industry.More attentions are paid to cycloid planetary transmission in precision transmission in recent years because half of its teeth are meshing simultaneously, because the outstanding error average effect leads to high precision, and because it has high torsion stiffness for there is no flexible element. The research on meshing theory of new cycloid enveloping planetary precision transmission is carried out according to differential geometry and gear geometry. It has important theoretic significance and practical value for revealing the essence of meshing and improving the characteristics of transmission, etc. Major contents of the thesis as follows:①According to gear geometry kinematics, a universal equation of cycloidal profile for one tooth and small teeth difference cycloid pin wheel gearing is established based on cylindrical pin tooth and given motion. A method called enveloping method to generate cycloid is put forward. The correct meshing condition and contact ratio of cycloid pin wheel gearing are discussed in detail, the calculating equations are also provided.②Investigation on the theory of conjugated meshing for 4 typical small teeth cycloid pin wheel gearings is carried out when the tooth difference numbers between pin wheel and cycloidal gear are 1, 2, 3 and -1, respectively. The investigation includes equation of cycloidal profile, meshing line, contact ratio etc., and case study is given.③Fundamental theory of secondary enveloping planetary transmission is established. The general equations of the first and second enveloping profile are derived based on an arbitary curve and planetary movement. The equation of meshing line and the existence condition of secondary enveloping profile are also discussed.④According to the general equation of secondary enveloping profile, the equations of secondary enveloping inner gear profile and meshing line are obtained. Detail investigation on the basic meshing characteristics of secondary enveloping cycloid planetary transmission is carried out.⑤According to the result of theoretical research, a set of secondary enveloping cycloid planetary transmission is designed, the modeling is carried out by Pro/ENGINEER software, and take part in the trial-production.